mathe/Library/PackageCache/com.unity.shadergraph@14.0.8/Documentation~/Hue-Node.md

Hue Node

Description

Offsets the hue of input In by the amount of input Offset. The unit of the offset can be set with the parameter Range. Offset in Degrees is in the range -180 to 180. In Radians it is -Pi to Pi.

Ports

Name	Direction	Type	Binding	Description
In	Input	Vector 3	None	Input value
Offset	Input	Float	None	Amount to offset hue
Out	Output	Vector 3	None	Output value

Controls

Name	Type	Options	Description
Range	Dropdown	Degrees, Radians	The unit used for the input Offset

Generated Code Example

The following example code represents one possible outcome of this node per Base mode.

Degrees

void Unity_Hue_Degrees_float(float3 In, float Offset, out float3 Out)
{
    float4 K = float4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
    float4 P = lerp(float4(In.bg, K.wz), float4(In.gb, K.xy), step(In.b, In.g));
    float4 Q = lerp(float4(P.xyw, In.r), float4(In.r, P.yzx), step(P.x, In.r));
    float D = Q.x - min(Q.w, Q.y);
    float E = 1e-10;
    float3 hsv = float3(abs(Q.z + (Q.w - Q.y)/(6.0 * D + E)), D / (Q.x + E), Q.x);

    float hue = hsv.x + Offset / 360;
    hsv.x = (hue < 0)
            ? hue + 1
            : (hue > 1)
                ? hue - 1
                : hue;

    float4 K2 = float4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
    float3 P2 = abs(frac(hsv.xxx + K2.xyz) * 6.0 - K2.www);
    Out = hsv.z * lerp(K2.xxx, saturate(P2 - K2.xxx), hsv.y);
}

Radians

void Unity_Hue_Radians_float(float3 In, float Offset, out float3 Out)
{
    float4 K = float4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
    float4 P = lerp(float4(In.bg, K.wz), float4(In.gb, K.xy), step(In.b, In.g));
    float4 Q = lerp(float4(P.xyw, In.r), float4(In.r, P.yzx), step(P.x, In.r));
    float D = Q.x - min(Q.w, Q.y);
    float E = 1e-10;
    float3 hsv = float3(abs(Q.z + (Q.w - Q.y)/(6.0 * D + E)), D / (Q.x + E), Q.x);

    float hue = hsv.x + Offset;
    hsv.x = (hue < 0)
            ? hue + 1
            : (hue > 1)
                ? hue - 1
                : hue;

    // HSV to RGB
    float4 K2 = float4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
    float3 P2 = abs(frac(hsv.xxx + K2.xyz) * 6.0 - K2.www);
    Out = hsv.z * lerp(K2.xxx, saturate(P2 - K2.xxx), hsv.y);
}